Regenerative Lipid Mediators for the Management of Severe Burn Wounds

摘要 严重烧伤的治疗主要依靠自体皮片移植，但由于受供皮区的限制， 不可用和大量合并症。目前的疗法无法消除实质性愈合 严重烧伤的缺陷，强调迫切需要更有效的治疗。我们的长期目标是 开发更好的治疗严重烧伤的方法。间充质干细胞（MSC）具有再生能力， 烧伤脂肪组织来源的微血管碎片（MVF）是天然的血管化单位， 丰富的骨髓间充质干细胞，内皮细胞，血管周围细胞，脂肪细胞在重建烧伤， 被破坏的皮肤MVF为MSC提供了更好的生态位，使MSC再生能力最大化。MVF也 通过微创吸脂术容易地从收集的脂肪组织中分离。我们发现了再生脂质 - 增加MSC或MVF增殖、存活和生长因子产生的介质（ReLiM），和 促进组织再生。ReLiM 1恢复受损的血管化和愈合。然而，ReLiM具有 在伤口中的半衰期短，限制了它们用于愈合烧伤和使MSC功能化的效用。为了解决这个 为了解决这个问题，我们开发了一种水凝胶，可以在烧伤伤口中维持ReLiM水平。ReLiM发布 由可生物降解的、无毒的基于氨基酸的聚（酯酰胺）蛋白质模拟物的水凝胶维持 聚合物（AA-PEAs）。缓释ReLiM与AA-PEA-水凝胶（Agel）基质的整合 促进MSC/MVF功能。我们假设缓释ReLiMs 结合Agel支架直接促进严重烧伤愈合，保护和引导MVF 再生功能我们的目标是开发ReLiM浸渍的Agels，提供ReLiM并提供 用于愈合严重烧伤并保护和引导MVF再生功能以更好地愈合的支架， 以及破译这种情况发生的机制。目标1。我们将开发Agel， ReLiM释放和1B）提供用于皮肤细胞归巢的最佳ReLiM释放仿生基质， 血管化和再上皮化，以及减少瘢痕形成和增加伤口破裂 实力目标二。2A）我们将开发一种构建体，其整合未培养的自体MVF，持续 释放ReLiMs和Agel支架，以最大限度地恢复深度烧伤。我们预测， 构造保护和引导MVF功能。我们将在体外使用人MVF验证结果， 翻译价值2B）我们将解读最佳MVF-ReLiM-Agel的功效机制。影响：这个 该项目将提供1）一种ReLiM-Agel敷料，可输送ReLiM并提供基质和覆盖物， 2）携带ReLiM和MVF的Agel基质，其保护和引导未培养的MVF， 有效的治疗，和3）潜在的机械知识。这些再生脂质介质 功能化敷料对移植物供体的要求不存在或最低，是有希望的辅助治疗 以克服目前用于治疗严重烧伤的移植方法或皮肤替代物的缺点。

ABSTRACT The treatment of severe burns relies on autologous skin grafts, which are limited due to donor-site unavailability and substantial comorbidities. Current therapies are unable to eliminate substantial healing defects in severe burns, underscoring the urgent needs of more effective therapies. Our long-term goals are to develop better therapies for severe burns. Mesenchymal stem cells (MSCs) possess regenerative power for burn wounds. Adipose-tissue derived microvascular fragments (MVFs) are native vascularization units and a rich source of the MSCs, endothelial cells, perivascular cells, and adipocytes essential in rebuilding burn- destroyed skin. MVFs provide a better niche for MSCs, maximizing MSC regenerative power. MVFs are also easily isolated from fat tissue collected via minimally invasive liposuction. We have identified regenerative lipid mediators (ReLiMs) that increase MSC or MVF proliferation, survival, and production of growth factors, and promote tissue regeneration. ReLiM1 restored impaired vascularization and healing. However, ReLiMs have short half-lives in wounds, limiting their utility for healing burns and functionalizing MSCs. To address this problem, we developed a hydrogel that can sustain ReLiM levels in burn wounds. ReLiM release was sustained from the hydrogel of biodegradable, non-toxic amino acid-based poly(ester amide) protein-mimic polymers (AA-PEAs). The integration of a sustained-release ReLiM with an AA-PEA-hydrogel (Agel) matrix accelerated healing and promoted MSC/MVF functions. We hypothesize that sustained release ReLiMs combined with Agel scaffolds directly promote healing of severe burns and protect and guide MVF regenerative functions. Our objective is to develop ReLiM-impregnated Agels that deliver ReLiMs and provide scaffolds for healing severe burns and protecting and guiding MVF regenerative functions for better healing as well as to decipher the mechanisms via which this occurs. Aim 1. We will develop the Agel to 1A) sustain ReLiM release and to 1B) provide an optimal ReLiM-releasing biomimetic matrix for skin cell homing, vascularization, and re-epithelization, as well as for the reduction of scarring and increasing wound breaking strength. Aim 2. 2A) We will develop a construct that integrates uncultured autologous MVFs, sustained release ReLiMs, and Agel scaffolds to maximize the healing of deep burns. We predict that the achieved construct protects and guides MVF functions. We will verify results using human MVFs in vitro for better translational value. 2B) We will decipher mechanisms for efficacy of the best MVF-ReLiM-Agel. Impact: This project will provide 1) a ReLiM-Agel dressing that delivers ReLiMs and provides a matrix and covering for efficient healing, 2) a ReLiM- and MVF-carrying Agel matrix that protects and guides uncultured MVFs for more efficient healing, and 3) the underlying mechanistic knowledge. These regenerative lipid mediator functionalized dressings with nonexistent or minimal graft-donor requirements are promising adjuvant therapy to overcome the drawbacks of grafting methods or skin substitutes currently used to treat severe burns.